protected override async Task OnFollowAsync(FollowEvent ev) { Log.WriteInfo($"SourceType:{ev.Source.Type}, SourceId:{ev.Source.Id}"); await SourceState.AddAsync(ev.Source.Type.ToString(), ev.Source.Id); var userName = ""; if (!string.IsNullOrEmpty(ev.Source.Id)) { var userProfile = await MessagingClient.GetUserProfileAsync(ev.Source.Id); userName = userProfile?.DisplayName ?? ""; } await MessagingClient.ReplyMessageAsync(ev.ReplyToken, $"Hello {userName}! Thank you for following !"); }